When Science Imitates Nature

What do porcupines, gelatin and fish have in common? They are examples of how the world around us can provoke medical ingenuity.

Natural Structures and Processes Inspire Medical Innovations

In
the recently published book, Biomaterials
Science: An Introduction to Materials in Medicine (third edition), pathologist
Frederick Schoen, MD, PhD, executive vice chair of the Department of Pathology
and director of the BWH Biomedical Research Institute Technology and Innovation
Program, and fellow co-editors dedicate a chapter to biomimicry, tipping their
hats to how processes and materials in nature-plants, animals and even
humans-can be a "source of inspiration for design and modification of
biomaterials and biomedical devices."

Scientists
examine nature in order to solve problems, a field known as biomimicry. Its
disciples study and glean observations from nature to develop solutions to
society's most perplexing challenges in agriculture, transportation and other
sectors. For scientists at BWH, nature has inspired some remarkable feats of
innovation that will advance patient care and medicine.

Medical Menagerie

Jeffrey Karp, PhD

Jeffrey
Karp, PhD, of the Division of Biomedical Engineering in the Department of
Medicine, is one of these scientists. His approach to the natural world, and
specifically to the animal kingdom, has breathed life into clever biomaterials
and medical devices that will improve health care.

Thumbing
through science articles about Karp's biomedical inventions is like scanning
the manifest of Noah's Ark. There's the microchip that can capture rare cancer
cells, viruses and bacteria in blood, which was inspired by a jellyfish's long,
sticky tentacles. Then there are the surgical and neonatal bandages that are
adhesive-even in wet environments-and prevent injury to a baby's fragile skin.
A gecko's foot and spider's web inspired
these innovations.

Recently,
Karp's curiosity about porcupines led him to discover the stick-and-stay
dynamics of their quills-new information that will be useful as bioengineers
develop the next generation of medical needles and adhesives.

"We
work on critical societal problems that can impact the quality of life of
suffering patients," said Karp. "When working toward solutions to medical
problems that can be rapidly translated to the clinical setting, naturally we
run into major challenges and barriers. The field of biomimicry can be used as
inspiration to overcome some of these challenges. Evolution is by far the best
problem solver."

To learn more about Karp's porcupine
work, check out this video below.

Human Jell-O

It's
not only fauna and flora that fuel scientists' imaginations. The architecture
of the human body has also inspired bioengineers who design artificial tissues.
Scientists have already developed sophisticated artificial tissues to replace
weakened heart valves, as well as skin grafts to treat burn trauma patients.

One of the key steps in making these tissues is to
lay a scaffold around which cells can form and grow to create the desired
tissue or organ. One type of scaffolding material scientists are exploring is
hydrogels.

Ali Khademhosseini, PhD, MASc, also of Biomedical Engineering, has studied hydrogels extensively, and has used
the medium to develop
artificial tissues and organs that will
one day be used to replace and repair damaged organs.

Ali Khademhosseini, PhD, MASc

Hydrogels are modeled after the body's own
extracellular matrix. The extracellular matrix is the part of animal tissue
that gives structural support to cells. Think of it as a gelatin dessert. Like
fruit suspended in gelatin, the cells are suspended in the extracellular
matrix.

Hydrogels mimic the extracellular matrix by
providing not only structure for cells, but also maintaining a stable
environment for them by reacting and adapting to changes in pH and temperature.

"By using advanced methods to control the
chemistry, architecture and physical properties of hydrogels, it is possible to
control the behavior of cells to instruct them on how to form new tissue," said
Khademhosseini. "Hydrogels have already proven to be useful. The medium has
been used as a surface coating to prevent blood clots on medical implants, and
it has also been used when engineering bone tissue."

Putting Out the Flame

Taking a voyage beyond cells and tissues, one comes upon the miniscule
molecules that regulate the complex biochemical processes that keep the body in
balanced, working order.

Charles Serhan, PhD

Charles Serhan, PhD, director of BWH's Center for Experimental
Therapeutics and Reperfusion Injury, used the concept of pharmacological
mimetics-creating drugs that mimic the body's natural chemical pathways-to
develop several new groups of therapeutics
that fight excessive inflammation.

Serhan discovered molecules in the body responsible for activating several chemical pathways that shut off
inflammation by stimulating a pro-resolving response. These
molecules-which he named resolvins-are made naturally by the body from fatty
molecules called omega-3 polyunsaturated fatty acids (also found in cold-water
fish and fish oils).

In preclinical and clinical models, these natural molecules have been
found to resolve arthritic pain, stop colitis (inflammation of the large
intestine), protect against viral eye infections and stimulate wound healing.

Now several pharmaceutical companies are developing and testing treatments
based on Serhan's resolvins to treat a wide range of inflammation-associated
diseases, such as inflammation from human dry eye syndrome.

"Knowing about the body's own pro-resolving methods against
inflammation has had far-reaching implications because resolving acute
inflammation was thought for hundreds of years to be a passive process in the
body," said Serhan. "The resolvin molecules we have discovered may potentially
shape medicine by providing a new class of drugs that activate pathways to
resolve inflammation and pain, as well as help clear infections."